The order Lepidoptera includes butterflies and moths. The members of the order Lepidoptera and, especially, butterflies are considered by most persons to be among the most interesting and beautiful animals. Considerable interest has developed in raising butterflies for commercial purposes. This is especially true for members of the family Danaidae including monarch butterflies, Danaus plexippus (L.), and queen butterflies, Danaus gilippus berenice Cramer.
The monarch butterfly is known for its beauty and for its long distance migrations and mass winter aggregations in sites located in California and in Mexico. Recently, interest in this species has extended to raising this butterfly for sale to elementary schools and for release at weddings and other ceremonies and celebrations.
Breeders of monarch butterflies have encountered severe problems with a naturally occurring neogregarine parasite, Ophryocystis elektroscirrha McLaughlin and Myers. After 3 to 4 generations of rearing the butterflies under laboratory conditions, this parasite builds to an inoculum level that causes large numbers of deformed, weak butterflies, leading to the demise of the colony. The re-establishment of a colony of monarch butterflies from wild populations would eventually lead to another build up of the disease and to the destruction of the colony.
The temporary suppression of the disease in laboratory reared monarch butterflies has been previously accomplished by treating eggs with 2% bleach for 30 minutes. Although this treatment resulted in an apparently "clean" colony of butterflies, the colony eventually had to be destroyed because it was contaminated with neogregarine spores which had developed resistance to bleach. Eighty percent of eggs treated with 2% bleach for 30 minutes resulted in adult butterflies with high numbers of spores and some were weak and deformed.
This neogregarine protozoa has also been found to infect queen butterflies. Many populations of the queen butterfly are found in habitats shared with monarch butterflies where they feed on similar nectar sources and the larvae of the two species have been reported on the same milkweed host. It is quite likely therefore that the neogregarine protozoa is transmitted between the two species.
I have developed a method of establishing and maintaining colonies of butterflies which are free of contamination with protozoa through examination of pupa exuviae or the bodies of adults and by selection of non-infected individuals as breeders.